Spark-pltjg



W. H. SNYDEIL SPARK PLUG. l APPLICATION FILED NOV.29| 1918.

Patented Sept. 14, 1920.

UNiTEnsTATss WARD H. sNxDiiR, or lconeness PARK, ILLrivoIs.v I

specification of Lettersfrteht.

Application fied November 29, iaipsfseriai no. 264,597; l

To all who/m, it may concern: `f

Be it known that I, VJARD SNYDER, a'

citizen of the United States, and a resident tion engines and has for its special objects,

rst, the provision of facilities for keeoingV the sparking terminals free 'from thev deposition of carbon and the accumulationof* lubricant which might by raccumulation thereon interfere with the passing vor sparking of the electricV current; and, second, the provision of facilities for wiping or cleaning a portion of the insulating core ofthe spark plug and thereby preventing theaccumulaftion of a carbon or oil deposit thereon which. would interfere with the action of the plug,

and, in the case of carbon deposit facilitate' a leakage of the current anda diminutionf of the amount thereof which would other? wise be compelled to pass between thespark-l ing terminals. 1 v y I attain the above objectsl by means of the structure and4 mechanism illustrated the accompanying drawings, infwhichf- Figure 1 is a centrallongitudinal'section of a forinof spark plug, embodying my,

v f vBhind the piston vheador disk land c within .'thefcylindrical recess k11 in the' insu# lating yco`re,is mounted a spring 2O of `'such .strength as .to permit the compression stroke invention; I

Fig. 2 is a central longitudinal section of a slightly modified structure also embodying my invention.

Fig. 3 is an enlarged view of the lower.lv y

adiskf15sufficiently lfar into the recess 11 so astoipositionthe disk-shaped extension 17 f end of one of the sparking terminals. Y

In the drawings, similar reference charf'V acters refer to similar, parts throughout the p Y f y Vinner end 19of the sparkingterminal 18.

Itawill now be seen that the movement of.

respective views.

The spark plug comprises an outer metallic shell the lower end 3 whereofis externally threaded to screw into the usual openi ing for the spark plug in an engi`necylin` der. The upperportion of the outer shell is enlarged at 4, and given a hexagonal or other suitable conformation so as to be easily engaged by a wrench.` vThe outer shell is bored at 5 to receive an insulating core, the upper portion of the bore at 6 being enlarged andfinteriorly threadedto receive a shoulder uponthe Vinsulating core and a retaining nut 7 to keep the insulating core in proper assembly with the outer shell. The insulating core 8 is provided with the eX-V terior shoulder 9 to enter the large portion centrallybored atA 1() and in the lower end krtl'i'ereof, at-11,` is provided'a cylindricalrecess.

Patented sept.14,192o. c f

' ofthe bore 6 andto be retainedfin position f' i by the nut 7. The insulatingcore isalso 'In thecentral lbore 10,of'the insulat-v f i ing core isv mounted ainetallic conducting l rod '12,the lower end 'of'which extends suitable distance belowthe end of the core andis either headed or provided with a nut at'its lower end 13. i Upon the upperend of tlie'fmetallic rod 12is'provided a suitable binding'nut 14 for thepurposeof securing theretoa wire'of the sparking circuit.

Ilflounted upon the lower projecting end oftherodlQ is a piston head ordisk 15 which is vadapted to fit-in the cylindrical rei cess 11-in the;` lower end of thek insulating core.,y Thepistoii head or disk 15-is pro- I vided with a downwardly` extending tubular 'neck 1G which preferably terminates in a disk-shaped lateral extension 17 'whichcof v operates with the headed end or nutl upony Ythe metallic vrod 12'to` prevent the removal thereof .from the saidrod. Depending from the outer shell isa vsparking terminal 18, the

outer end of which is preferably looped upwardly and .extended inwardly into the path of thek disk-shaped extension 17. Upon the lower end ofthe sparking `terminalr18 may also kbe mounted a wheel or diskf19 to facili` tate the passage thereby ofthe disk 17.

offthe'engine todrive the piston head or inv proper sparking relation tothe wheel or the disk-shaped yextension k17 by kthe wheel 19` willdet'ach from therespective parts anyl carbon deposition which may have occurred on either of thesey parts; and it will yalso'be seen that the movement ofthe piston lheady vof the insulating 'core free from the deposi` tion of carbon or'other foreignmatter.

In order that the end of the sparking terminal may not always strike the same spot lupon theV disk-shaped extension 17 I have providedmeans for causing aslight rotation of the latter,lwliich means consist in providinga'plurality,offserrations or teeth l Y2Q upon the upper surface of the headed end or nut 13 of rod 12 that coacts with a projcction 23 upon the alining under-surface of disk-shaped extension 17, as shown in detail in Fig. 3. Owing to the helical form of the spring 20, the expanding thereof inI returning the movable elements 15, 16 and 17 to their normal positions, will rotateit slightly at its lower end, thus causing a rotaftioiial movement of the disk-shaped extension 17. The projection 23 upon diskshaped extension 17, in coaction with the serratioiis 22, will accentuate the rotational movement caused by the spring and thereby present another surface of the disk-.shaped extension 17 to the opposite sparking member.

In the modified construction shown in Fig. 2,'tlie disk-shaped extension 17EL and piston header disk a and metallic rod` 12a, are or may be made integral, and the spring u, instead of being installed within the cylindrical recess 11a, behind the piston header disk 15a, is installed in a suitable cap 21 upon the top of the spark plug where the said spring will not be subject to as highrheat Y threaded plug, a sparking terminal extend-Y as if installed within the cylindrical re cess 11a. Y Y

VWhat l claim is 1. A spark plug for internalcombustion engines Vcomprising a metallicY exteriorly ing therefrom, an insulating core therefor having a cylindrical recessin its lower end, a central current conduct-ing rod mounted within saidv core and extending below the same, a piston -head niovably mounted upon said current conducting rod and adapted to cooperate with Vthe walls of said cylindrical recess, a sparking point extended from said lmovably'mounted piston head, and means for returning said movably mounted piston head to the outer portion of said cylindrical Yrecess after the same has been forced therein by the compression developed in the cylin-V der of the engine. Y

2. A spark plug comprising a Yhollow nietallic casing, a sparking point carried thereby, an insulating core mounted within said casing having a cylindrical recess in its lower eiid, a piston head mounted to recip` rocate in said'recess, a sparking member carried by said piston head, electrical con-` nection with said disk and sparking meinber, and means for returning said'piston Y head to its normal position after theV sainer has been forced into said recess by pressure Adeveloped in the cylinder of the engine.

3. A spark plug comprising a hollow metallic casing, a sparking point carried thereby, an insulating coreinounted within said casing having a cylindrical recess in its 'lower end, a current conducting rod disposed centrally in said insulating core and extending through and beyond said recess,

piston head movably mounted upon said rod within said recess, a sleeve depending from said piston headand surrounding said rod, and an annular extension on the lower extremity of said sleeve the movement of which extension causes the same to engage said sparking point.

4. A spark plug'comprising a hollow inetallic casing, a sparking point carried thereby having a roller journaled in the outer end Y thereof, an insulating core mounted within saidrcasing having a cylindrical re- Y the recess therein, a sparking member car- I ried byand movable on said terminal so as to engage and pass said sparking point, an

extension on said member operable iii said recess, and aspring in said recess between said extension and the inner end of said recess whereby said extension is norniallypositioned adjacent the outer end of said recess.

6. In a spark plug a casing provided with a sparking point, an insulating core mounted in said casing, a terminal rod carried by said core, a sparking member movable lon-v gitudinally upon saldi rod, and means for causing a rotation of said member upon said rod ineluding'a helical spring that normally retains said member adjacent the lower end of said. rod.

Signed atv Chicago, county of Cook and State of Illinois, this 20th day of NovembtyY 1918.vkvv j Y WARD H sNi'Dnii.

l lVitnesses z FRANK l, FARMS, BENJ. T. RooDHOUsE. 

